基准排放因子更新对隧道需风量的影响研究

Influence of Base Emission Factor Update on Tunnel Fresh-Air Demand

为解决交通车辆持续更新导致的城市隧道内通风系统设计浪费和运营闲置,研究基准排放因子更新对隧道需风量的影响,并建立2种应对车辆更新的基准排放因子计算方法.首先,通过理论分析明确需风量计算式中随时间更新的关键参数为基准排放因子;随后,根据定量分析得到基准排放因子和纵坡-车速系数更新对需风量的影响;最后,结合国外理念和实际设计经验,提出2种考虑时间更新的基准排放因子计算方法.研究结果表明:我国道路隧道通风设计规范在制定基准排放因子时参考了世界道路协会(PIARC)通风报告,并分析得到了参考理由;与2000年相比,2021年的CO、NOx和PM基准排放限值分别降低了81.6%、76.7%和97.9%;建立了使用机动车污染物排放限值作为基准排放因子的最不利设计方法,计算出2018年各污染物基准排放因子(CO为0.0011 m^(3)/(辆·km),PM为0.4610 m^(2)/(辆·km)),相比于2014年《细则》分别降低84.3%和77.0%.建立并验证了基准排放因子计算方法,为城市道路隧道通风系统设计提供参考.

To solve the design waste and idle operation of ventilation systems in urban tunnels caused by the continuous update of traffic vehicles,the influence of base emission factor update on tunnel fresh-air demand was studied,and two calculation methods of base emission factor in response to vehicle update were established.To begin with,the key parameters updating over time in the fresh-air demand formula were determined as base emission factors through theoretical analysis.Then,the influence of base emission factors and gradient-speed factor update on fresh-air demand was obtained based on quantitative analysis.Finally,according to foreign concepts and actual design experience,two calculation methods for base emission factors considering time were proposed.The results show that Chinese road tunnel ventilation design standards refer to the PIARC ventilation report when formulating the base emission factors,with the reasons explained.Compared with those in 2000,the base CO,NOx,and PM emission limits in 2021 are reduced by 81.6%,76.7%,and 97.9%respectively.The most unfavorable design method using vehicle pollutant emission limits as base emission factors is established,and the base emission factors of each pollutant in 2018 are calculated as follows:the base CO emission factor is 0.0011 m^(3)/(veh·km),and the base PM emission factor is 0.4610 m^(2)/(veh·km),which are reduced by 84.3%and 77.0%compared with China Standard in 2014.The research results establish and verify the calculation method of base emission factors,which provides a reference for the design of urban road tunnel ventilation systems.